1. Field of the Invention
The invention relates to an audio processing system, and more particularly to an audio processing system for used in a multi-channel audio chip.
2. Description of the Related Art
The audio technology is advanced from the single-channel to the dual-channel, four-channel, and six-channel (5.1 channels on the DVD player) audio output system. Meanwhile, the audio storage medium has advanced from the analog storage medium, such as a platter, an audiotape and the like, to the digital storage medium, such as CD, DVD and the like.
In order to achieve the multi-channel audio outputs, an audio chip is used to convert the audio signals stored in a digital format in the digital storage medium into multi-channel audio analog signals. The audio chip typically includes a plurality of digital-to-analog converters to convert the digital audio signals into analog audio signals, which are outputted to the speakers to provide sound and/or music for human being.
FIG. 1 is a schematic illustration showing a conventional audio processing system for used in a multi-channel audio chip. As shown in FIG. 1, six digital signals DS1 to DS6 from six channels CH1 to CH6 are inputted to the corresponding digital-to-analog converters (DACs) 111 to 116. The DACs 111 to 116 respectively convert the digital signals DS1 to DS6 into corresponding analog signals AS1 to AS6. The speakers 121 to 126 are connected to the corresponding DACs 111 to 116, respectively, to provide the audio outputs according to the analog signals AS1 to AS6 from the DACs 111 to 116. Thus, the multi-channel audio outputs may be constructed.
In the conventional architecture, a plurality of DACs are needed and the number of DACs is increased with the increasing of the channel number. However, the configuration of DAC is complicated and the size of the circuit is large. Consequently, the cost of the multi-channel audio chip cannot be reduced when the conventional architecture is utilized.